Seat, squab or couch upholstery

ABSTRACT

Upholstery for a seat, rest or couch. The upholstery includes internal channels through which draining air may flow. Valve means that open under load or compression control air flow through the channels. The flow of draining air is increased automatically or given a desired flow distribution by the surface area pressure controlled by a seated person. The cross sections of the valve means and the channels may be designed so that even a very small pressure difference and correspondingly little energy expenditure will provide a satisfactory air flow rate.

The invention relates to seat, rest, or couch upholstery and its generalobject is to improve the ventilation of that type of upholstery.

It is a nuisance to perspire when sitting on a chair, a swivel armchairat a desk, or a seat in a car, usually equipped with strong thermalinsulation. Bed ridden patients and senior citizens who have to spend alot of time reposing often complain about a lack of ventilation of theirbeds and frequently suffer bedsores.

It is a problem with the ventilation of seats or beds that the customarytype of upholstery is compressed under the weight of the person sittingor lying on it, whereby ventilation normally is greatly affected inspite of reduced thermal insulation. Intensive thermal insulation oreven active cooling at little ventilation of diffusion-permeable seatcovers may lead to condensation in the colder part of the upholstery,often accompanied by fungus proliferation in these areas which by nomeans are hermetically sealed, and that is objectionable from thehygienic point of view.

To overcome this inconvenience, seat upholstery has been proposed(W95/14 409, WO 96/05475) with which a fan blows conditioned air underpositive pressure through passages and pores in the upholstery to thebuttocks and back of the person seated on it. In spite of the very greatexpenditure, only a minor effect or great energy input may be expectedfrom this known seat upholstery because there is insufficientcoordination between the passages supplying and carrying off thedrainage air and the person sitting on or leaning against theupholstery. Uncomfortable undercooling due to an intensive by-pass flowmust be expected particularly in the marginal regions of a sittingperson.

Likewise known is mat-like padding (U.S. Pat. No. 5,004,294; EP 0 689786 A1) containing a plurality of valves which are controlled to openunder the load of a person seated on them. Then conditioned air is blownout through the valves against the buttocks and back of the seatedperson. With this padding, the valve travel is short compared with thecompression of the upholstery so that the padding practically does notcontribute to the cushioning effect. The conditioned air which is blownout may cause undesirable undercooling of the body parts mentioned. Theproblem of discharge of the air enriched with the effluvium from humanbodies was not taken into account.

It is known per se to subject foam upholstery to forced ventilation bymeans of blast air which acts by pressure or suction (DE 31 47 610 A1).A solution for motor vehicle upholstery, working with positive pressure,accomplishes that with a differential pressure of 100-600 mbar (DE 3 705756 A1).

It is the object of the invention to provide an apparatus for effectiveand pleasant ventilation of seats, rests, or beds which restrictsdraft-free ventilation substantially to the parts of the seats or bedscontacted by the body, and which can be manufactured and operated at lowcost. The apparatus is to be suitable, at the same time, forretrofitting of existing seating and bedding pieces of furniture.

This object is met by seat, rest, or couch upholstery as defined inclaim 1. Advantageous modifications of the invention are specified inthe subclaims.

According to the invention the flow of draining air is increasedautomatically or given a desired flow distribution by the surface areapressure exerted by the seated person. That is accomplished bycontrolling the valve means, preferably connected in parallel, to openbecause it is only under pressure load or compression that they liberatethe cross section of the passage opening. This causes the draininig airnot to be guided past the loaded surface but instead to travel throughdirectly to where the ventilation is intended to have its effect. Theflow cross sections of the valve means and the drainage channels may bedesigned so that even a very small pressure difference in the order offrom 50 to 200 Pa and correspondingly little energy expenditure willprovide a satisfactory air flow rate.

Retrofit upholstery according to the invention may consist of agas-permeable, thin cover layer having a high coefficient of heattransmission to serve as the contact surface for the seated person andan underlying, sufficiently thick drainage layer offering little flowresistance and embodied, for example, by open-pore foam or a coarsefiber layer. This drainage layer may be terminated by a substantiallydiffusion-tight film at the side remote from the seated person.

Only at relatively low room temperatures will heat and steam exuded bythe body be evacuated to a sufficient degree through the drainage layerdue to the mere buoyancy caused by a difference in density between thewarm moist (lighter) and the colder room temperatures. At higher airtemperatures that is often inadequate so that the energy-consuming roomair conditioning system must be operated although intelligentenergy-saving seat air conditioning would suffice. The ventilating flowwhich dissipates heat and removes moisture may be enhanced by connectingthe drainage layer to a low-noise ventilator operating either in thepressure or suction modes and at a rotational speed or volume flow ratewhich either may be adjustable manually or automatically controllable byway of a temperature sensor and/or moisture sensor and an inputreference value element.

In further modification of the invention the draining air flow rate maybe adapted to the physical data (size, weight) of the seated person withthe aid of a rotary slide valve installed in a cylindrical manifold.

With automobile seats it is self-suggesting to connect the seat and restupholstery designed according to the invention at the inlet end to theinterior ventilating system and an air conditioning system, whereavailable.

In the case of swivel deskchairs where a travelling range, howeversmall, is needed, the seat air conditioning system may be connected by ahose to a suction fan which may be mounted at the ceiling of the room,for instance. Considering the improved sitting comfort, theselimitations of the travelling space may be put up with.

As known from U.S. Pat. No. 5,004,294, the valve means may comprise aplurality of valves, for example mushroom-type valves. These valves areopened by the weight of the seated or reclined person against therestoring action of spring elements which have a decisive influence,according to the invention, on the cushioning effect of the upholstery.With pressure operation of the air conditioned seat or bed, the drainingair is pressed through the respiration-active cover layer in smallspaces, and with suction it is withdrawn accordingly. A channel systemthrough which the draining air may be supplied and removed,respectively, is disposed at the side of the valve sealing surfacesremote from the seated or reclined person. Such valve systems in checkerboard arrangement offer a solution which saves energy particularly wellsince the cross section of the drainage channels is liberated for thedraining air exclusively in the region of the surface loaded by a seatedor reclined person. On the other hand, in a system including channelswhich are connected in parallel, actuation of a valve in the seat or bed. . . one of the channels throughout the full channel length, i.e. alsothrough the respiration-active upper upholstery of the back rest, thedraining air will be conveyed without any need for the seated person tolean against it.

The problems with seating pieces differ from those encountered withbedding pieces in that the association between a seated person and theseating piece, at least in the case of swivel deskchairs and car seats,is relatively precise geometrically, whereas a person lying on amattress may take all kinds of positions. For this reason an embodimentis preferred for mattresses which is made up of a plurality of valvemeans arranged over a large area and reacting to being loaded byopening. Also for swivel deskchairs and individual car seats thestructure should be such that the draining air sucked off or blownthrough is not removed unused, bypassing the seated person, but insteadis passed through those zones which require intensive dissipation ofheat and removal of moisture.

With one embodiment of the invention, the draining air distribution isadapted to persons of differently broad body shape by placing on theseat, rest, or couch an upper template provided with drain apertures inan arrangement specifically adapted to the personal body size.

In especially preferred embodiments of the invention foam elements ofthe upholstery itself serve as valves, forming a large-area multigonalmosaic, preferably realized as a hexagonal matrix. These foam elementsmay comprise air-impermeable intermediate layers which, upon pressureloading of this element, contracts the same transversely, therebyliberating cavities for the passage of air so that the draining airchannels are brought into fluid communication through the open-poresections of the foam elements and also through the cavities in questionwith the drainage channels of the lower upholstery or cavities in a seatshell and through the latter with the pressure or suction operationmanifold.

The invention will be described further, by way of example, withreference to diagrammatic drawings, in which:

FIG. 1 is a vertical section through a swivel deskchair comprisingupholstery designed in accordance with the invention;

FIG. 2a) is a part sectional elevation, on an enlarged scale, of theupholstery shown in FIG. 1;

FIGS. 2b) and 2c) are sectional elevations along lines IIb) and IIc) inFIG. 2a) at two different valve positions of a drainage channel in theupholstery;

FIG. 3a) is a part sectional elevation along line IIIa) in FIG. 3b), theneck rest containing a manifold;

FIG. 3b) is a part sectional view of the neck rest of the chair as inFIG. 1;

FIG. 4 is a part sectional view of upholstery according to theinvention, the right half of the part section shown being loaded by theweight of a person;

FIG. 5 is a part sectional view of modified upholstery according to theinvention, the part of the upholstery shown at the right being loaded bythe weight of a person, just like in FIG. 4;

FIG. 6 shows another modification of upholstery according to theinvention, once again the partial cutout of the upholstery shown at theright being loaded by the weight of a person;

FIG. 7a) is a cross section along line A-B in FIG. 7b) and

FIG. 7b) a diagrammatic top plan view of another modification ofseat/rest upholstery according to the invention;

FIG. 8 is a part sectional view of a pocketed spring core type mattressdesigned according to the invention;

FIGS. 9 and 10 show two examples of further modified upholsteryaccording to the invention, both designed for easy manufacture andassembly, in this case an unloaded part of the upholstery beingillustrated at the right side and a loaded part at the left;

FIG. 11 is a longitudinal sectional elevation of mattress upholsterydesigned according to the invention;

FIG. 12 is a top plan view of an air mattress designed according to theinvention, and

FIG. 13 is a part sectional elevation, on an enlarged scale, of aninflated air mattress according to FIG. 12.

FIG. 1 shows a swivel deskchair equipped according to the invention witha ventilation system. The contact surfaces 3 and 4 with the seatedperson are covered by a respiration-active fabric layer 1 offeringsufficiently high flow resistance to air being sucked through. Belowthis fabric layer 1 there is an upper cushion 2 of open-pore materialwhich has a higher stiffness so that it will not be compressed too muchunder the weight of the seated person. The flow resistance of this uppercushion formed, for instance, with longitudinal ribs in the direction ofthe spinal column of the seated person, is lowered according to theinvention by the weight of the seated person. The open-pore uppercushion 2 includes drainage channels 15 which are connected according toFIG. 1 to a manifold 5 housed in the neck pad 6. From the neck pad, adraining air conduit 7 leads to the suction end of a ventilator 8 whosemotor is connected to an accumulator 9 adapted to be recharged via anelectrical connection 10. Together with the motor and accumulator theventilator 8 is housed in a sound-proofed space in the flow of theswivel chair.

The draining air conduit 7 may be laid outside of the backrest and seatto the ventilator if a seating piece of furniture is to be retrofit withsuch an air conditioning system. In that event a combination isself-suggesting of the ventilator plus accumulator in a flat arrangement(not shown) to be mounted at the backrest.

FIG. 2 illustrates a valve 18 with valve flaps 19 such as used ininflatable water wings. It is installed in each of the parallel drainagechannels 15 of the upper cushion 2 (FIG. 1) and remains closed when theseat is in unloaded condition (FIG. 2c). Under pressure loading of aseated person, the valve 18 automatically opens the wider (FIG. 2b) thehigher the local pressure load turns out to be. That is intentionalaccording to the invention because the dissipation of heat and removalof steam are to be the most intensive at locations where there is highpressure loading.

FIG. 3 illustrates a draining air manifold 5 built into the neck pad 6of the swivel chair shown in FIG. 1, including an internal rotary slidevalve 13 the passage opening 17 of which has a profile 14 designed suchthat the draining air will be distributed to the draining air channels15, connected in parallel, in response to the body weight and mass byadjusting the rotary slide valve in a corresponding angular position.

FIG. 4 presents a cutout of upholstery according to the invention havinga contact surface 3 or 4 with the person seated on or leaning againstit. It is covered by a respiration-active fabric layer 1 and padded withan open-pore upper cushion 2. A layer consisting of a plurality of valveclosure members embodied by valve discs 20 is disposed below andseparate from the upper cushion 2. Upon loading by a person seated on orleaning against it, the valve closure members open against returnsprings, embodied by helical springs 21, in accordance with the contactpressure profile of that person, thus liberating a flow cross section 22for the draining air which is supplied and removed, respectively,through drainage channels 41 in the hollow foundation. The valve seatsmay be embodied by circular openings 23 in a partition 24 supported byspacers 40 on the seat shell or a base 42. The length of travel of thehelical springs 21 has a decisive codeterminative influence on thecushioning effect.

FIG. 5 presents a cutout of another embodiment of the invention,comprising a contact surface 3 or 4 with the person seated on, leaningagainst, or lying on it. The valves are realized by foam elements of theupholstery structured accordingly. An unloaded cutout is illustrated atthe left and a loaded cutout at the right.

The foam elements 36 which preferably are made hexagonal and glued withopen pores to the conventional upper cushion 37 and which, therefore,may be combined to form a regular matrix have the following structure.The pressure exerted by the seated person presses a conical stamp 25 ofopen-pore foam material, enclosed by a somewhat softer ring 35 ofopen-pore foam material, against a largely air-impermeable, flexibleintermediate layer 26 which, however, is hard to stretch in longitudinaldirection, into an open-pore stamp pad 28 filled with soft foam 27 and,thereby, pulls the boundary 29 of the element towards the axis 30. Inthis manner an annular cavity 31 is formed around each of the loadedelements. Through this cavity 31 fluid communication is establishedamong the open-pore stamps 25 and stamp pad portions 27, 28 and with thedrainage channels 41 in the seat shell or lower cushion 33, 34, whichare discharging the draining air 32.

FIG. 6 presents another variant. Here the transverse contraction of thehexagonal elements 36 is caused by a cylindrical dent surface 38enclosing an open-pore core 39 which is soft to transverse compression.The stiffness of the dent surface 38 is such that, under pressureloading of the elements 36, the dent surface dents towards the axes 30thereof so that an annular cavity 31 is formed through which theopen-pore regions enter into fluid communication with the coarse-porouslower cushion 33, 34 which discharges the draining air, bypassing thesealing intermediate layer 26.

The valves of foam material constitute the principal cushion whichgenerates the cushioning effect of the variant embodiments according toFIGS. 5 and 6.

The embodiments illustrated in FIGS. 5 and 6 can be made at littleexpenditure in the following way:

First the upper cushion 2 is prepared. To that end, open-pore foam oflow transverse contraction stiffness is injected into a moldcorresponding in shape to the stamps 25 or cores 39. Subsequently, theannular intermediate layer 26 of somewhat harder, open-pore foam isinjected into the spaces in between.

The bottom of the upper part thus formed is laminated with anair-impermeable layer which is soft to transverse compression. Thereuponthe intermediate layer 26 is cut along the central surface by ahoneycomb-like hexagonal punching tool. This upper part then is glued ona congruent lower part, prepared in the same fashion, the glue beingapplied only in the central area of the cores.

In the case of modified manufacture, hexgonal members are prefabricatedand subsequently configured in mosaic fashion to form a structure havinga surface area. The hexagonal members according to FIGS. 5 and 6 areglued with open pores to air-permeable cover and base layers of greatsurface areas.

FIG. 7 illustrates another embodiment of upholstery according to theinvention. The air flow is indicated by arrows. The seat or seat pad 45is equipped with a draining air-permeable base template 46 adapted topersons of broad build. The slighter ones will bring into position a toptemplate 47 of corresponding smaller surface area, provided with drainapertures 48, and equipped with a coarse-pore upper cushion 49 fortransverse conveyance of draining air under the seated person. The backrest may have a corresponding structure.

A coarse-porous base layer 51 for conveyance of the draining air 52 isprovided along the drawer-like, air-impermeable seat or rest shell 50.Helical springs disposed parallel to each other or twisted into eachother lead towards the draining air manifold or manifolds 53, thuspresenting a fluidic connection with little pressure loss. To enhancethe sitting comfort, soft, open-pore lower upholstery 54 or upholsterywith draining air apertures extending substantially vertically withrespect to the seat or rest is located on top of this "coarse-porous"base layer 51.

The base template 46 described above lies on this lower upholstery ascover layer of the lower cushion 55. The upper cushion 56 is placed onthe lower cushion, and the bottom surface of the upper cushion forms theperson-specific top template 47. This top template 47 is provided with apattern of apertures or slits 57 for passing air, as seen at the leftside of the top plan view, permitting optimum dissipation of heat andremoval of moisture, e.g. along the spinal column down to the coccyx andin the region of the crotch and also at the highly loaded "cheek bones".An open-pore drainage layer 49 having a low flow pressure losscoefficient is provided on the top template as well so as to letdraining air enter from the sides with little pressure loss and thenflow under the person seated on or leaning against the upholstery, allthe way to the flow sinks 57 in the upper template. This upperupholstery likewise may have a rib-like or spiral structure particularlyfavoring the entry of air from the unloaded sides. The recommended covermaterial is a net-like fabric having good heat conductivity.

The modification of the invention presented in FIG. 8 is advantageousfor beds, especially for pocketed spring core mattresses, but is usefulas well for any sophisticated seat structure.

The helical spring in each bag 60 is realized as a unitary "reversingspring" 61 having, for example, a conical core 62 surrounded by acylindrical spring section 63. The cylindrical spring section rests onthe upper bottom 64 of the hollow lower bottom 65, while the slightlyshorter, conical interior spring section pulls a valve disc 66 into thevalve seat 67 when the mattress is not loaded. Upon loading of themattress by a person 70 sitting or lying on it, the valves in theindividual bags open to different degrees, depending on the localpressure exerted. The valve disc thus is pressed against an elasticmember 68 the stiffness of which, in combination with that of thereversing spring, determines the opening and closing characteristics ofthe valve. However, a largely local sink flow at the loaded place is notachieved with this configuration unless the sidewalls of the bags 60 orof groups of bags have a relatively great flow resistance, as obtainablewith linen fabric by spraying it with natural latex, for instance. Whatis important is that the pressure loss of the mattress for the airsucked through the mattress is low at sufficiently loaded places inorder that satisfactory conveyance of draining air will take place evenat a low pressure difference of the ventilator in operation, asindicated here by arrows, in correspondence with a low energyrequirement. In non-loaded zones, the mattress of course is to belargely impermeable to air.

The hollow lower bottom 65 consisting of a closed outer cover 69 and ofthe upper bottom 64 which includes the valve seats 67 may be madeflexible, for example of sufficiently stiff natural caoutchouc so thatwith this mattress, too, adjustment of the support is possible withoutany problems.

FIGS. 9 and 10 show two embodiments of upholstery according to theinvention that are favorable in terms of manufacture and assembly.

FIG. 9 is a cross sectional presentation of the element of anadvantageous variant embodiment, loaded at the left side and unloaded atthe right side. Like the embodiments shown in FIGS. 4 to 8, theupholstery contains valves with valve closure members 82 and sealingvalve seats 87. Here the upholstery of a seat or bed consists of a lowerupholstery 81 which is produced of somewhat stiffer closed-pore foam andan upper upholstery 80. The upper upholstery 80 has a bar-like valveclosure member 82 made of closed-pore foam in the shape of a rib-likethickened portion at a web 83 and connected to a compensating layer 85which is a softer, open-pore material provided additionally or insteadwith drainage through-bores 84. The lower upholstery 81 includescylindrical cavities 86 extending throughout its length and serving asdrainage channels. The cavities are open upwardly through elongate slitsor constrictions. At either side of these constrictions line-shapedvalve seats 87 are formed. The webs 83 with the valve closure members 82project through the constrictions into the cavities 86. The lowerupholstery 81 is laminated at the bottom with a largely air-permeablecover layer 88 which is made to be flexible with mattresses. Inaccordance with the pressure load transmitted from a person 70 seated orreclined, the rib-like valve closure members 82 are pressed into thecylindrical cavities 86 of the lower upholstery and consequently liftoff the valve seats 87. Thus fluid communication is established from thesurroundings to below a person 70 seated or reclined on the upholsteryand, underneath the loaded upholstery section, to the cavities 86 whichmay be connected to a ventilator operated in the suction or pressuremode.

For simple assembly, the compressible valve closure members 82 of theupper upholstery are squeezed from above through the valve seats 87 ofthe lower upholstery or pushed in laterally. In unloaded state, thevalve closure members 82 sealingly engage the valve seats 87 under minorbias. Again the valves are integrated in the upholstery, as with thevariants shown in FIGS. 5 and 6.

With the embodiment shown in FIG. 10, the lower upholstery is made up ofstrip-shaped elements 89 constituting the line-shaped valve seats 87 andthe cavities 86. Especially with seats and rests made by applying theupholstery to a firm shell, as in FIG. 10, the strip-shaped elementsmentioned are stiff and may be made integral with or connected to theseat shell. Here, the full spring and valve closing path is accommodatedin the upper cushion 80. Moreover, the valve closure members 82 aredesigned to be sufficiently compressible if they are to be squeezedthrough the valve seats 87 into the larger drainage cavity 86 in thelower bottom on first assembly.

This configuration remains easily dismantable for cleaning or recyclingbecause bonding between the upholstery and the seat shell is notnecessary.

It is obvious that the design principle which comprises pressing thevalve closure members through the valve seats for assembly, isapplicable not only with two-dimensional but also with conventionalcircular valves. In this case the valve closure members 82 in FIGS. 9and 10 are to be understood as being rotationally symmetric (spherical)elements, while the constrictions with the valve seats 87 are conicalbores. Assembly in this case can be accomplished only by squeezing butnot by laterally pushing the upper upholstery into the lower upholstery.

With presently available manufacturing processes for foam products thevalve layer of elements 82, 87 might be made very thin, e.g. with athickness of no more than 10 mm, up to the thickness of a strong coverfabric. In this case a laminated valve pad might be laid, as a thin seatcushion, on lower upholstery which now would be realizable very easilyand which is connected by a surface area to a draining air supplysource. To permit entry of draining air under a seated person, the sideof the laminated valve pad facing that person could comprise a ribstructure for example, to form a groove-like upper drainage which mightbe covered by an open-pore, yet tough, i.e. not stretch-like coverfabric. The latter acts as a dust filter to prevent rapid interiorcontamination of the valve layer and as a barrier layer against blockingof the flow of the upper drainage e.g. by fibers of woollen fabric beingpressed into these clearances under the pressure of a person sitting onit.

If the pressure loading of the upholstery is provoked by an object whichitself is not air-permeable the conditioning air in the upper drainagelayer 37 (FIGS. 4 to 6) may be carried off laterally because thisdrainage layer is made to have very good transverse permeability as atangential drainage layer. FIGS. 4, 5, and 6 show upholstery with whichair permeability of a contacting article was started from, such as isgiven with controlled cooling of porous products, whereas airpermeability of the loading article is excluded with FIGS. 7 to 10.

It is a problem with the upholstery according to the invention that noair is passed through in the unloaded event, as would be desirable, forinstance, to cool a vehicle seat before the passenger sits down. Tosolve that problem, it is provided in accordance with the invention thatthe ventilator be equipped with an overload stage so that switch-on ofthis stage will generate a much increased suction vacuum in the cavitiesdue to which the valves will open even without loading by a seatedperson.

The matress 110 designed according to the invention, as shown inlongitudinal section in FIG. 11, and comprising, for instance, amulti-upholstery layer 118 with integrated valves according to FIG. 9,has an air inlet channel 111 at the foot end communicating with all thedrainage channels 112 in the lower upholstery 113. The air inlet channelcan be connected to ambient atmosphere via an adjustable throttle valveindicated at 114. When this throttle valve 114 is fully open the flow ofdraining air through the bed 115 on which the person is lying would belargely reduced because the low pressure in the drainage channels 112would be greatly lowered by the opening of the throttle valves. Thatpermits easy adaptation to seasonal conditions. Moreover, the moisturefed into the mattress during the sleeping period may be expelled fromthe zone downstream of the valve layer 117 by switching on theventilator in the manifold 116 and opening the throttle valve 114.

Normally, mattesses should be positioned upright from time to time toventilate them. That is difficult to do, especially for older people,and it becomes superfluous with the configuration described according toFIG. 11. Switch-off times or adjustment values for the ventilator may bepreset by means of a moisture sensor (at 119) installed upstream of thesuction fan (not shown) and/or a temperature sensor (at 120).Alternatively, a timer may be provided to limit the operating period ofthe ventilator to two hours. The exhaust air stream thus may becontrolled adjustably in response to moisture and temperature to adaptit to the requirements of the sitting or lying person.

The modification illustrated in FIGS. 12 and 13 presents a furtherdevelopment of the design of FIGS. 9 and 10 to an inflatable airmattress. Here the lower upholstery 81 to be seen in FIGS. 9 and 10 hasbeen replaced by inflatable hollow chambers 90 obtained by gluingtogether the air-tight bottom 88 and the air-tight protuberances 91which form the valve seats 87.

The upper upholstery 80 is replaced by a system of inflatable hollowchambers 92 obtained by gluing together a bottom layer 93 which formsthe valve closure members 82 and a top layer 94. In the region of thebond, the upper upholstery is provided with apertures 95. Draining airmay flow through these apertures from the upper upholstery into thecavities upon loading of the mattress. The top layer 94 which isundulated after inflation is covered by a porous cushion layer 1.

Draining air finds its way through the cavities 96 between the porouslayer 97 and the top layer 94 to underneath the lying person 70 towardsthe flow sinks which develop by pushing the valve closure members 82away from the valve seats 87 in accordance with the person's loadprofile. The draining air is passed through the cavities 86 which arecombined by way of a manifold 100 (FIG. 12) to a mini-ventilator 101.Here, too, ventilation, in many cases sufficient, can be achieved bythermic effects without connection to a ventilator operating in thesuction or pressure mode.

The air mattress according to FIGS. 12 and 13 can be folded together toa small volume and, during trips to areas where hygiene is not perfect,it offers protection on hotel beds against infections and parasites,especially when operating in the suction mode. And this is not achievedat the expense of impermeability to air, otherwise typical of airmattresses, and the resulting profuse perspiration.

Let us assume, for purposes of estimating the maximum air flow requiredto ventilate a mattress according to the invention, that the air in aroom at a temperature of 27° C. has a relative humidity of 90%. Underthese conditions a human being would evaporate approximately 1 liter ofwater in the course of one night. Half of that could be stored in themattress without any remedial measures being taken. If one assumes thedraining air to be warmed up by 5° C. and brought to 95% relativehumidity, the volume of draining air required is calculated to be about50 kg distributed over 10 hours, in other words, approximately 6 m³ ofair per hour. Together with the suction vacuum required of about 100 Pa,at a pumping efficiency of 30%, this volume of draining air results inelectrical power of no more than about 0.5 W. If the lying person coversa surface area of 0.5 m² the resulting average orthogonal flow velocityis no more than about 4 mm/s. Such a velocity of air is not perceived asunpleasant draft. Extremely low-noise mini-ventilators are commerciallyavailable for this kind of application.

The following statements are made with respect to the dimensioning ofthe drainage channels or aperture size of the valve means:

FIGS. 4 to 6 as well as 8 to 13 are sectional elevations of upholsterywhich are largely true to scale, and they show valve means integrated inthe upholstery according to the invention and suitable for elasticallydampening a great distance, as compared to the layer thickness of theupholstery, of from 20 to 80% of the total thickness of the upholstery.

In view of the low differential pressure aimed at in the order of 100Pa, supplied by the operating ventilator, the flow velocities occurringin the drainage channels always must be low since the dynamic pressureof the flow already amounts to about 60 Pa at a flow velocity of 10ms⁻¹. The coefficient of pressure loss of the branched system ofdrainage channels should be as small as possible in consideration of thefact that the flow is not rectilinear but takes a tortuous course andpasses many variations in cross section, as may be gathered from FIGS. 9and 10, for instance. Ideal conditions exist where the tangentialdrainage channels 37 (FIGS. 4 to 6) or 49 (FIG. 7) next to the seatedperson as well as the bores 84 and the drainage cavities 86 in the baseof the upholstery (FIGS. 9 and 10) have the smallest possible pressureloss so that the local cooling air flow rate will be controlledexclusively by the weight of the contacting person via the crosssections of the valve openings between the valve closure members and thevalve seats.

In the case of the embodiment according to FIG. 4 the valve means aregiven dimensions such that the valve closure members 20 can travel for alength l of about 50% at the most of the thickness of the upholstery.Even at the end of this travel, the valve still has a residual openingcross section sufficient for ventilation because the plate-like cover20a at the end of the valve axis 20b, improving the seat comfort, has asmaller diameter dp than the valve seat ds.

Also in FIGS. 5 and 6 the dimension of the valves made of upholsteryfoam may be seen largely true to scale. While the upper drainage layer37 and the lower drainage channels or layers 33, 34 primarily are to bemade flexible and hardly compressible, the upholstery valve layer 36, 39is designed to be both flexible and compressible. The dimensions B andH_(PV) of the valves which, for example, are made hexagonal should be inthe order of from 40 to 90% of the overall thickness H of the upholsterystructure, which normally is between 50 and 200 mm. The thickness d_(TD)of the tangential drainage layer 37 disposed towards the contactingperson should be between 3 and 15 mm. The same applies to the lowerdrainage layer or drainage channels which may be composed of a finelystructured layer 33 and a coarser layer 34.

In accordance with the embodiment shown in FIG. 8 the essential elementwhich determines the cushioning effect, namely the helical spring 61,itself is the elastic adjusting member for the valve disc 66. Thehelical spring 61 has a height Hs which corresponds to from 60 to 80% ofthe thickness H of the mattress. The spacings which are usual withinnerspring mattresses or pocketed spring core mattresses may bemaintained.

The statements made with respect to FIGS. 4 to 6 and 8 apply mutatismutandis to FIGS. 9 and 10. With the latter variant, however, the heightH_(PV) of the upholstery valve, in this case designed to be linear orcylindrical in the longitudinal direction of the upholstery, may amountup to about 95% of the overall thicknes H of the upholstery since thelower drainage 86 is integrated in the lower upholstery 81 which formsthe valve seat. The distance t_(v) between adjacent linear valves mayvary between approximately 0.3·H and 1.5·H. The diameter d_(B) and thepitch t_(B) of the drainage bores may vary within wide limits, as knownin the art of upholstery, of course with the aim of realizing thesmallest possible pressure loss.

In conclusion it should be emphasized that the energy consumption forthe upholstery providing a pleasant lying climate to a mattressaccording to the invention is lower by orders of magnitude than theexpenditure. involved in a room air conditioning system. In modern splitdesign such a room air conditioning system costs many times as much asthe additional equipment of a matress designed according to theinvention.

What is claimed is:
 1. Air-permeable upholstery comprising channelsthrough which air can flow via a valve means which control the flow ofair through the channels, the valve means being positively controlled toopen by loading of the upholstery, the valve means including closing andrestoring members being constituted by pliable elements, characterizedin that the closing and restoring members form component parts of theupholstery itself, and that the upholstery including the closing andrestoring members are supported on a base (42, 69, 88, 113) and theupholstery characterized in that a plurality of cylindrical foamelements (36) including stamps (25) and stamp pads (27, 28) are arrangedbelow an open-pore upper cushion (37), the stamps and stamp pads beingseparated from each other by an air-impermeable, flexible intermediatelayer (26) such that, under pressure loading by a sitting or lyingperson, the intermediate layer (26) is pressed into the soft stamp pads(27, 28), thereby becoming deformed so that the intermediate layer (26)dents one of said plurality of cylindrical foam elements (36) to form anannular cavity (31), whereby fluid communication is established betweensaid open-pore upper cushion (37) and an open-pore base layer (33, 34)and drainage channels (41).
 2. The upholstery as claimed in claim 1,characterized in that each foam element (36) comprises a cover surfaceand a shell surface (38) enclosing a core (39) which is adapted to yieldunder transverse compression, and that said shell surface (38) becomesdented towards an axis (30) of the foam element (36) under pressureacting on said cover surface so that an annular cavity (31) resultsthrough which fluid communication is established between open-poreregions of upper and lower drainages (33, 34; 37, 38), bypassing theair-impermeable intermediate layer (26).
 3. Air-permeable upholsterycomprising channels through which air can flow via a valve means whichcontrol the flow of air through the channels, the valve means beingpositively controlled to open by loading of the upholstery, the valvemeans including closing and restoring members being constituted bypliable elements, characterized in that the closing and restoringmembers form component parts of the upholstery itself, and that theupholstery including the closing and restoring members are supported ona base (42, 69, 88, 113) and the upholstery comprising a pocketed springcore type upholstery, characterized in that each spring (61) is designedas a unitary reversing spring having a cylindrical exterior section (63)and a conical core section (62), that the cylindrical exterior section(63) is guided in a substantially air-impermeable bag (60) and rests ona hollow lower bottom (65) and the conical core section (63), inunloaded state, pulls a valve disc (66) into a valve seat (67) such thatthe valve disc (66) will be pressed into open position under pressureloading by a sitting or lying person, whereby communication isestablished with a cavity, forming a drainage channel, in the lowerbottom (65).
 4. Air-permeable upholstery comprising channels throughwhich air can flow via a valve means which control the flow of airthrough the channels, the valve means being positively controlled toopen by loading of the upholstery, the valve means including closing andrestoring members being constituted by pliable elements, characterizedin that the closing and restoring members form component parts of theupholstery itself, and that the upholstery including the closing andrestoring members are supported on a base (42, 69, 88, 113) and theupholstery characterized in that each valve means comprises a valveclosure member (82) and a valve seat (87) through which the valveclosure member extends and against which it abuts sealingly when theupholstery is in unloaded condition and in that the valve closure member(82) is formed by a rib-like thickened portion at the end of a web (83)which passes through an elongate constriction of a cavity (86) forming adrainage channel.
 5. Air-permeable upholstery comprising channelsthrough which air can flow via a valve means which control the flow ofair through the channels, the valve means being positively controlled toopen by loading of the upholstery the valve means including closing andrestoring members being constituted by pliable elements, characterizedin that the closing and restoring members form component parts of theupholstery itself, and that the upholstery including the closing andrestoring members are supported on a base (42, 69, 88, 113) and theupholstery characterized in that the channels are connected to at leastone manifold (5) comprising a ventilator (8) and that loading whichopens the valve means is obtainable by controlling the ventilator to anespecially high negative pressure.
 6. The upholstery as claimed in claim5, characterized in that said ventilator (8) is a suction fan.